#include<stdio.h>
int main()
{
	int x;
	scanf("%d",&x);
	if (x>=95&&x<=100)
	{
		x=1;
	}
	else if (x>=90&&x<=94)
	{
		x=2;
	}
	else if (x>=80&&x<=89)
	{
		x=3;
	}
	else if (x>=70&&x<=79)
	{
		x=4;
	}
	else if (x>=60&&x<=69)
	{
		x=5;
	}
	else if (x>=0&&x<=59)
	{
		x=6;
	}
	switch(x)
	{
		case 1:
			printf("A+");
			break;
		case 2:
			printf("A");
			break;
		case 3:
		    printf("B");
			break;
		case 4:
		    printf("C");
			break;
		case 5:
		    printf("D");
			break;
		case 6:
		    printf("E");
			break;
		default:
		    printf("Invalid score"); 
	}
	return 0;
}
